The load cell is a collective term for a load cell and a load cell, and its measurement characteristics are evaluated using a single parameter. According to the conversion method, the load cell can be divided into 8 types: photoelectric type, hydraulic type, electromagnetic type, capacitive type, magnetic pole change type, vibration type, gyro ceremony, and resistance strain type. The most widely used is the strain resistance type. Weighing sensors have already penetrated into an extremely wide range of fields such as industrial production, space development, marine exploration, environmental protection, resource investigation, medical diagnosis, biological engineering, and even cultural relic protection.

Resistance strain-type load cell mainly consists of four parts: elastic component, resistance strain gauge, measurement circuit and transmission cable. The strain gauge is attached to the elastic element. When the elastic element is deformed by force, the strain gauge on the strain gauge is deformed and the resistance changes. The measuring circuit measures the change in the strain gauge resistance and converts it into an electrical signal output that is proportional to the magnitude of the external force. After processing, the electrical signal shows the quality of the measured object in digital form. The resistance strain-type weighing sensor has a weighing range of several tens of grams to hundreds of tons, and the measurement accuracy is 1/1000 to 1/10000. The structure is simple and the reliability is good. Most electronic scales use this type of sensor. The resistance strain load cell is based on the principle that the elastic body of the elastic body generates the elastic deformation under the action of the external force, so that the resistance strain gauge conversion element pasted on his surface is also deformed along with it, and the resistance strain gauge is deformed. The resistance will change to increase or decrease, and then the corresponding measurement circuit converts this resistance change into an electrical signal voltage or current, thereby completing the process of transforming the external force into an electrical signal. During the measurement process, weight loading on the elastomer of the load cell causes plastic deformation. During the working process of the resistance strain load cell, the strain in the positive and negative directions is converted into an electronic signal through the strain gauge mounted on the elastic body. The simplest bending beam load cell has only one strain gauge. In general, elastomers and strain gauges are combined in a variety of ways, such as housing seal components, to protect strain gauges.

There are many factors to consider when selecting a load cell. In actual use, we mainly consider the following factors. Range of Load Cell According to your application, the range selection of the load cell can be determined based on the maximum weighing value of the scale, the number of sensors selected, the weight of the scale body, the maximum partial load that can be generated, and the comprehensive evaluation of the dynamic load factor. In general, the closer the sensor's range is to the load assigned to each sensor, the higher the accuracy of its weighing. However, in actual use, due to the load imposed on the sensor, in addition to the object being weighed, there are loads such as the weight of the scale body, the tare weight, the eccentric load, and the vibration impact. Therefore, when selecting the sensor, many factors must be taken into account to ensure that The safety and life of the sensor. Second, the accuracy level of the load cell includes the sensor's nonlinearity, creep, repeatability, hysteresis, and sensitivity. In the selection of high-level sensors should not blindly pursue, we should consider the electronic level of accuracy and cost. Under normal circumstances, the root mean square value of the sum of the three parameters of the non-linearity, non-repeatability, and hysteresis of the selected sensor is slightly higher than the accuracy of the scale. The choice of weighing sensor form depends mainly on the type of weighing and the installation space, to ensure proper installation, safe and reliable weighing; on the other hand to consider the manufacturer's recommendations. For sensor manufacturers, it generally stipulates the force conditions, performance indicators, installation forms, structural forms, elastomer materials, etc. of the sensor.